Network Calculus-Based Latency for Time-Triggered Traffic under Flexible Window-Overlapping Scheduling (FWOS) in a Time-Sensitive Network (TSN)

Deterministic latency is an urgent demand to pursue the continuous increase in intelligence in several real-time applications, such as connected vehicles and automation industries. A time-sensitive network (TSN) is a new framework introduced to serve these applications. Several functions are defined in the TSN standard to support time-triggered (TT) requirements, such as IEEE 802.1Qbv and IEEE 802.1Qbu for traffic scheduling and preemption mechanisms, respectively. However, implementing strict timing constraints to support scheduled traffic can miss the needs of unscheduled real-time flows. Accordingly, more relaxed scheduling algorithms are required. In this paper, we introduce the flexible window-overlapping scheduling (FWOS) algorithm that optimizes the overlapping among TT windows by three different metrics: the priority of overlapping, the position of overlapping, and the overlapping ratio (OR). An analytical model for the worst-case end-to-end delay (WCD) is derived using the network calculus (NC) approach considering the relative relationships between window offsets for consecutive nodes and evaluated under a realistic vehicle use case. While guaranteeing latency deadline for TT traffic, the FWOS algorithm defines the maximum allowable OR that maximizes the bandwidth available for unscheduled transmission. Even under a non-overlapping scenario, less pessimistic latency bounds have been obtained using FWOS than the latest related works.

Reconfiguration algorithms for high precision communications in time sensitive networks: Time-aware shaper configuration with IEEE 802.1Qcc

As new networking paradigms emerge for different networking applications, e.g., cyber-physical systems, and different services are handled under a converged data link technology, e.g., Ethernet, certain applications with mission critical traffic cannot coexist on the same physical networking infrastructure using traditional Ethernet packet-switched networking protocols. The IEEE 802.1Q Time Sensitive Networking (TSN) Task Group is developing protocol standards to provide deterministic properties, i.e., eliminates non-deterministic delays, on Ethernet based packet-switched networks. In particular, the IEEE 802.1Qcc, centralized management and control, and the IEEE 802.1Qbv, Time-Aware Shaper (TAS), can be used to manage and control Scheduled Traffic (ST) streams with periodic properties along with Best-Effort (BE) traffic on the same network infrastructure. We investigate the effects of using the IEEE 802.1Qcc management protocol to accurately and precisely configure TAS enabled switches (with transmission windows governed by Gate Control Lists (GCLs) with Gate Control Entries (GCEs)) ensuring ultra-low bounded latency, zero packet loss, and minimal jitter for ST TSN traffic. We examine both a centralized network/distributed user model (hybrid model) and a fully-distributed (decentralized) 802.1Qcc model on a typical industrial control network with the goal of maximizing the number of ST streams.

A Period-Aware Routing Method for IEEE 802.1Qbv TSN Networks

The IEEE 802.1Qbv standard provides deterministic delay and low jitter guarantee for time-critical communication using a precomputed cyclic transmission schedule. Computing such transmission schedule requires routing the flows first, which significantly affects the quality of the schedule. So far off-the-shelf algorithms like load-balanced routing, which minimize the maximum scheduled traffic load (MSTL), have been used to accommodate more time-triggered traffic. However, they do not consider that the bandwidth utilization of periodic flows is decentralized and their criteria for bottleneck of scheduling are imprecise. In this paper, we firstly explore the combinability among different periods of flows, which can measure their ability to share bandwidth without conflict. Then, we propose a novel period-aware routing algorithm to reduce the scheduling bottleneck, thus more flows can be accommodated. The experiment results show that the success rate of scheduling is significantly improved compared to shortest path routing and load balanced routing.

Energy Efficient and Quality of Service Compromise Techniques for Wireless Body Area Networks

In the present era the use of e-health plays a major role in the field of medical science. Today a significant attraction interest is towards Wireless Body area network (WBAN). The major challenges of Wireless Body area network (WBAN) technique are to maintain the quality service and to track the network stability for a longer time, e.g., probability of delivery, and latency. The main important issue is to maintain the energy efficiency within the formed network. Here we propose a protocol for WBANs based on MAC using the multi-dimension (MD) graph optimization to compromise the energy consumption and QoS in data transmission. In WBANs, low battery performing on-body or inculcate biomedical sensor nodes are applicable to observe and gathers the physiological signals like body temperature, blood pressure, ECG and EEG. The MAC protocol design utilizes an optimization algorithm to optimize the scheduled traffic and channel of WBAN. The proposed protocol simulation results will be better than TDMA, CA-MAC and IEEE 802.15.6 MAC in terms of energy efficiency and QoS for large network conditions.

IoT Based Automated Traffic Light Control System For Emergency Vehicles Using LoRa

There is a serious issue of Emergency Vehicles being stuck at intersections due to traffic congestion or scheduled traffic signal. This may result in delay in motion or the Emergency Vehicle may remain in statutory position. Otherwise, if the emergency vehicle ever tries to override the signal, it may result in accident or traffic congestion. To overcome this problem automated traffic control system is proposed. The system is designed to find a cost efficient and accurate solution to save lives. In the system, siren of the approaching emergency vehicle is priorly sensed by using smart objects and the traffic lane in which the emergency vehicle isapproaching is made free by halting the traffic in other lanes of the intersection.